1. Field of the Invention
The present invention relates to reproduction of multimedia data, and, more particularly, to a storage medium including an interactive graphic stream providing menus using various transition effects regardless of reproducing modes of multimedia data. The present invention also relates to an apparatus to reproduce multimedia data.
2. Description of the Related Art
In order to reproduce multimedia data, AV data, navigation data to control reproduction of the AV data, and system data are recorded in the storage medium. The system data includes introduction information of a title of AV data to be first reproduced when a storage medium is inserted in a reproducing apparatus. Besides this data, additional data may be included in the storage medium. In particular, various kinds of information required to reproduce video, audio, subtitles, and menus are multiplexed into one main stream and recorded in the AV data.
FIG. 1 is a configuration of AV data in which various elemental streams are multiplexed. Referring to FIG. 1, a video stream 102, an audio stream 104, a presentation graphic stream 106 to provide subtitles, and an interactive graphic stream 108 to provide a menu screen of an interaction with a user are multiplexed into one main stream and recorded in a storage medium in which multimedia data is recorded. Hereinafter, the multiplexed main stream is called AV data 110.
In particular, the interactive graphic stream 108 to provide a menu screen to allow an interaction with a user includes a plurality of segments. FIG. 2 is a configuration of the interactive graphic stream 108 out of the elemental streams shown in FIG. 1.
Referring to FIG. 2, the interactive graphic stream 108 includes a plurality of segments. A unit displayed on one screen from an interactive composition segment (ICS) to an end segment is called a display set. One display set includes, but is not limited to including:
1) An ICS to record composition information of an interactive graphic;
2) A palette definition segment (PDS) to define palette information of color and/or clearness which is to be applied to the interactive graphic;
3) A plurality of object definition segments (ODSs) to define object data, including image information such as buttons, to be displayed on a screen;
4) An end segment indicating the end of the display set.
In particular, the ICS includes output termination time information of a relative display set, button composition information, and operation information of a reproducing apparatus according to a user operation. The ICS may be realized using an ICS data structure.
Each segment included in one display set is recorded in a packetized elementary stream (PES), which is a packet unit of an MPEG-2 transport stream (TS). The relative display set starts to be decoded at a decoding time stamp (DTS) included in the PES and starts to be outputted to a display screen at a presentation time stamp (PTS).
Also, an output termination time of the relative display set is determined by a value of a composition_time_out_pts field recorded in the ICS. The composition_time_out_pts field will be described later. Accordingly, the interactive graphic stream 108 is output to the screen at a designated time (PTS), receives a user operation, performs corresponding operations, and disappears from the screen at the determined output termination time (composition_time_out_pts).
Due to the data structure as is described above, the ICS has the following disadvantages. First, where a plurality of page menus are provided, since movement to preceding and subsequent menu pages is possible only through a user operation according to a general menu characteristic, a PTS defined in a PES packet including an ICS has a meaning only in a first menu page, and PTSs in subsequent pages do not have any meaning. Therefore, in order to construct a plurality of page menus, an application type of a main stream should be set to a browsable slide show. That is, in a case where a main stream is a movie application, a plurality of page menus cannot be realized. Second, a transition effect between menu pages in a plurality of page menus cannot be provided.